Brakes of certain vehicles are operated by a so-called `S` cam which is displaced by a brake shaft. The brake shaft is normally supported by nylon bushes acting as plain bearings. Where these conventional bushes are to be replaced after wear the task involves removal of the vehicle wheels and disassembly of the drum brakes to provide proper access to the bushes. In harsh environments the bushes need frequent replacement since the bearing surfaces undergo premature wear due to the ingress of contaminants and the high radial applied load due to heavy braking.
GB 2 195 151A describes an assembly which acts as a sealed roller bearing assembly for replacing the conventional plain bearing bushes. This known assembly is complex and costly and there is a need for a simpler design which reverts back to plain bearings.